Press control mechanism



Sept. 5, 1939. F, R, HIGLEY 2,171,558

PRESS CONTROL MECHANISM Filed Sept. 25, 1957 6126 2& 24

aw i" /9 1 /Ja 3 INVENTOR /7 FRANK R. HIGLEY ATTOR Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE PRESS CONTROL MECHANISM of Ohio Application September 23, 1937, Serial No. 165,343

4 Claims.

This invention relates I to pressing machine controls.

An object of the present invention is the provision of a power-operated pressing machine having control means for the power means operable by spaced safety manuals with novel means for holding the manuals both in their operated and unoperated positions.

One of the features of my invention is the provision in a press of the type described of a pair of safety manuals movable through two stages of operation. In the first stage of operation the manuals are adapted to cause movement of the power means in press-closing direction but during this period the press will not remain closed if one or both of the manuals is released. During the second stage of manual operation a maintaining effect is produced upon the manuals to hold them in their actuated position. My present invention provides novel fluid-actuated means for returning the manuals to unactuated position during first-stage operation, for moving the manuals from intermediate to full operated position and for holding them in full operated improvements in position.

My invention also comprises the novel combination of a fluid-actuated holding means as above described with a press control valve.

Other novel features of my invention will appear from the accompanying specification and drawing and the essential features will be summarized in the claims.

In the drawing Fig. 1 shows an end elevation of a pressing machine with the control mechanism therefor shown diagrammatically; Fig. 2 is a similar view showing the pressing machine just prior to reaching safe-closed position with the corresponding position'of the control mechanism shown diagrammatically, while Fig. 3 is a View of the control mechanism of Figs. 1 and 2 in fully operated position.

I have shown my control mechanism as applied to a press having a frame It supporting a pressing bed H and also a yoke [2 which carries a head [3 into and out of engagement with the bed ll upon actuation of toggles [4 by means of the fluid motor IS. A spring [6 returns the head toward open position. The supply of pressure fluid to motor i5 is by way of conduit ll, valve casing l8 and conduit IS. The casing l8 houses a piston valve [800 adapted to connect conduit H! with exhaust port 18b or with supply conduit IT. The piston valve stem I80 is connected to whiflletree 20, each end of which is connected by a toggle with one of the operating manuals. Manual 2i forms a part of toggle 22 and manual 23 forms a part of toggle 24. Permanent stop members 25 limit the movement of the toggles as they break outwardly and permanent stop 26 limits the movement of the toggles in the other direction. A movable block member 2'! lies between the toggles 22 and 24 in the position of Figs. 1 and 2 when the press is between open and safe closed positions. Means is provided for removing this block when the press is safe closed. To this end the block is shown as forming a part of bell crank'28 pivoted to the frame of the machine and connected by a rod 29 which passes through a slotted bracket 39 in the toggle Hi. This rod carries collars 29a and 29?). A spring 3| biases the block 21 to the position of Figs. 1 and 2.

Novel fluid actuated means is provided for maintaining the toggles 22 and 24 both in their operated and unoperated position, and also for moving them from an intermediate position to the fully operated position. While this might be a separately constructed fluid actuated device, in the form shown a conduit 32 is connected betweenconduit IT and the lower end of easing I8. Thus line pressure is at all times exerted beneath the valve piston [8a in a direction upwardly as shown in the drawing. That is to say, with the piston valve la in any of its various positions, the pressure exerted upon the inner faces of the two pistons balance each other and the line pressure exerted upon the outer face of the lower piston in chamber 33 is available to actuate the toggles 22 and 24. The pressure in chamber 33 thus unbalances the valve toward fluid cut-off position.

With the press in open position the manuals willbe in the position of Fig. l, the toggles will be broken outwardly as shown and maintained in that position by the pressure in chamber 33 of the valve casing. The operator then moves the manuals through a first stage of operation to the position of Fig. 2 where the stop member 21 limits them short of their center line position. The valve l8a however, has moved to supply position as shown in Fig. 2 and energizes motor IE to close the press. If either of the manuals is released before the press is safe closed the pressure in chamber 33 will return the manuals to the position of Fig. 1 and the press will open. When the press is safe closed, however, bracket 39 engages collar 29a pulling on rod 29 and removing the block 21. The operator can feel the removal of this block through the pressure of her hands on the manuals and will then move the manuals a further distance through a second stage of operation to the position of Fig. 3 where they pass over center limited by the stop 26. It will be noted that the valve I8 is so constructed that it may be moved from the supply position of Fig. 2 to that of Fig. 3 while at all times exhaust port l8b remains closed so that no pressure fluid is lost. In other words, the control valve has no delicately adjusted supply position but permits movement of toggles 22 and 24 over center while at all times supplying fluid to motor with exhaust port I81) closed. As soon as the manuals pass over center the pressure in chamber 33 is available to continue their movement to the full operated position and to hold them there. The manuals may then be released and the press will remain closed. To open the press either of the manuals is again returned to the position of Fig. 1 by pulling upon it whereupon the pressure in chamber 33 is effective to return valve [8a to the position of Fig. l, causing the press to open and again inserting block 27 between the manuals with the toggles 22 and 24 again broken outwardly.

What I claim is: v

1. In a pressing machine, a pair of relatively movable coacting pressing members, fluid actuated power means for causing a pressing operation between said members, a reciprocable control valve for causing actuation of said power means, manual means foroperating said control valve and comprising two manuals spaced to require a hand of the operator on each of them for coincidental actuation thereof, said control valve having fluid supply and fluid cut-oif positions, means normally biasingsaid valve toward cutoff position, said manual means being movable in two stages of operation, a first stage adapted to actuate said control valve to supply position when both manuals are operated coincidentally whereby the pressing machinemay be closed, and a second stage after the press reaches safe closed position and adapted to move said valve beyond its first stage position without disturbing its supply channel arrangement, means normally preventing effective second stage operation of said manual means until said pressing members reach safe closed position, and said manual meanshaving a part moved over center by second stage operation' and adapted to be held in operated position by the pressure exerted by said biased valve.

2. In a pressing machine having coacting relatively movable pressing members and fluid actuated power means for causing a pressing action 7 between them, a piston type control valve for supplying fluid to said power means, a fluid sup ply to the piston of said valve urging it to fluid cut-off position, a pair 'of spaced safety manuals having operated and unoperated positions and an intermediate position, means providing an operative connection between said manuals and the piston of said valve and arranged to require conjoint operation of both manuals at least to intermediate position to move said valve to fluid supply position, said manuals having a part connected therewith and moved over center by movement of said manuals to operated position where it is adapted to be held by the force urging the piston of said valve to fluid cut-off position, and means preventing movement of said manuals from intermediate to operated position until said pressing members reach safe-closed position.

3. In a pressing machine having coacting relatively movable pressing members and fluid actuated power means for causing a pressing action between them, a piston type control valve for supplying fluid to said power means, a fluid supply to the piston of said valve urging it to fluid cut-on position, a pair of spaced safety manuals, an equalizer bar, toggle connections between said manuals and the ends of said bar, an operative connection between the intermediate portion of said bar and the piston of said valve, said manuals and valve being so related that movement of said toggle connections short of straightened position moves said valve to fluid supply position, means preventing movement of said toggles beyond straighened position until said pressing members reach safe-closed position, and stop means limiting movement of said toggles to slightly beyond straightened position, whereby they hold said valve in fluid supply position while said fluid supply to said piston holds said toggles beyond straightened position.

4'. In a pressing machine having relatively movable'coacting pressing members and fluid actuated power operating means therefor, fluid supply for said power means including a reciprocable control valve, means normally biasing said valve toward fluid cut-ofl position, control means for said valve including spaced safety manuals, and an over-center device between said valve and said manuals so arranged that said manuals have a stable inoperative position on one side of center and a stable operated position on the other side of center, said manuals and said device when short of central straightened position being adapted to move said valve to fluid supply position, means preventing advance of said device over center until the press is safely closed, and said valve having a second supply position beyond the first-named supply position permitting said device to advance over center Without disturbing the supply to said power means.

FRANK R. HIGLEY. 

